Repeated "Bounce processing info" system emails?

I am getting the same “Bounce processing info” system message each time my cron runs my commandline:

/usr/bin/php /var/www/vhosts/example.com/httpdocs/lists/admin/index.php -pprocessbounces -c/var/www/vhosts/example.com/httpdocs/lists/config/config.php >/tmp/processbounces-out.txt

This problem began after a server migration and phplist upgrade from 3.2.5 to 3.3.1

The body of the system email is:

Report:
Report of advanced bounce processing:
email bob@foo.com blacklisted by bounce rule 1
User: http://example.com/lists/admin/?page=user&id=149401
Rule: http://example.com/lists/admin/?page=bouncerule&id=1

I searched bob@foo.com and clicked the “Remove subscriber” button.
The repeated emails have stopped for now.
I will see after my next mail run, whether this bounce processing problem persists.